have phenylketonuria (a rare genetic condition where the body is unable to break down a substance called phenylalanine), as phenylalanine is found in certain bulk-forming laxatives

are taking opioid painkillers, such as codeine or morphine

These situations don't usually mean you can't use laxatives, but certain types of laxative may be more suitable for you than others.

Children and laxatives

Laxatives aren't recommended for babies who haven't been weaned. If your baby is constipated, try giving them extra water in between feeds. Gently massaging their tummy and moving their legs in a cycling motion may also help.

Babies who are eating solid foods may be able to use laxatives, but you should first make sure your baby drinks plenty of water or diluted fruit juice and increase the amount of fibre in their diet. If they're still constipated, your GP may prescribe or recommend a laxative.

In older children, osmotic or stimulant laxatives are often recommended alongside dietary changes as the first treatment for constipation.

Always check with your GP before giving your baby or child a laxative.